This invention relates generally to construction and in particular to a method and apparatus for construction of in-ground swimming pools having vinyl liners.
Conventional in-ground swimming pool construction often begins by marking, e.g. with chalk lines or stakes, a ground surface with the general outline or layout of the necessary excavation. The dimensions and shape of the excavation are generally determined by the desired pool surface area plus a perimeter area for construction of the pool walls. Excavation can then be accomplished by digging a hole having a desired shape and depth within the marked area. The excavation can include a shelf having a uniform width at the outer periphery of the swimming pool hole. The shelf is normally intended to be generally horizontal and can be positioned at a depth of about three feet vertically beneath the ground surface. The shelf, therefore, generally conforms to the shape of the pool and is provided for the support of wall-forming falsework comprising standard height wall forms used to form concrete pool walls for vinyl liner pools.
The assembled falsework can comprise an inboard wall in uniform spaced relationship to an outboard wall. Both the inboard wall and the outboard wall can be constructed from numerous individual panels. The individual panels can be sized sufficiently small to facilitate transportation to and from a work site, and for ease of assembly and disassembly. The individual panels forming the inboard and outboard walls of the falsework are normally all of uniform height. Various shapes and sizes of wall form panels can be provided so that, when assembled, the falsework generally conforms to the pool layout as marked prior to excavation.
Once the wall forms are assembled on the shelf, they usually require adjustment so that an upper edge of the assembled falsework is horizontal. Such an adjustment is often necessary because the work shelf supporting the falsework or form assembly is usually not uniformly horizontal, as excavated. If an upper edge of one portion of a falsework assembly is lower than another portion, freshly poured cement may spill over the upper edge of the lower portion of the falsework when the falsework assembly is filled with semi-liquid concrete. Thus, prior to pouring concrete, the upper edge of the falsework assembly should be uniformly horizontal.
Thus, to provide a uniformly horizontal upper edge of the falsework assembly, the work shelf on which the false-work assembly is positioned must be uniformly horizontal or adjustments are required. In the past, problems have been encountered in excavating a work shelf which is horizontally true. The problems associated with excavating the horizontal shelf are pronounced when the excavation site is located on a sloping grade. Further, since the shelf cannot be practicably made uniformly horizontal, vertical adjustments in the falsework assembly are called for. When adjustments in the falsework assembly are required, problems are encountered in making vertical and horizontal adjustments because of the massive and unwieldy nature of the assembled falsework.
The problems are worsened when the swimming pool is built onto a surface which is sloping because of the difficulty in excavating a horizontal shelf.
To date, no art to the applicant's knowledge has been directed to a method of building in in-ground swimming pools having vinyl liners which substantially eliminates the need to vertically or horizontally adjust assembled falsework prior to filling with concrete. Falsework structures have been proposed which incorporate panels designed with stake leveling devices. However, because such devices significantly increase the cost of the installation, such devices are not totally satisfactory.